Method of reducing alkali-silica reaction for embedding aggregate in concrete and mitigating detrimental effects of freeze-thaw in concrete

ABSTRACT

A method for forming a concrete slab at a location subject to freezing temperatures is disclosed. Additionally, a method for forming a concrete slab with aggregate embedded at the exposed surface of the concrete slab is disclosed. The method contemplates utilization of a waterproof concrete mix.

CROSS-REFERENCE TO RELATED APPLICATIONS

Not Applicable

STATEMENT RE: FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not Applicable

BACKGROUND

The methods and embodiments disclosed herein are directed to a concreteslab having a surface seeded aggregate and/or formed at a locationsubject to freezing temperatures.

Concrete slabs may be formed with embedded surface seeded aggregate atthe exposed surface of the concrete slab. Various methods of embeddingthe aggregate into the exposed surface of the concrete slab aredescribed in U.S. Pat. Nos. 6,033,136; 7,670,081; 7,607,859 and7,614,820. These methods require an additional step of applying achemical treatment of hydrolyzed alkali silica solution to the exposedsurface of the concrete. The solution must be applied in a specificmanner to prevent the detrimental effects between reactive aggregate andthe concrete. The application of the hydrolyzed alkali silica solutionassists in maintaining embedment of the exposed aggregate in theconcrete slab even with high pedestrian traffic. If the hydrolyzedalkali silica solution is applied incorrectly, then the solution will beineffective.

For example, the application of the solution must be uniform over theexposed surface. Moreover, the hydrolyzed alkali silica solution mustpenetrate through the exposed surface of the concrete slab to aparticular depth. If the hydrolyzed alkali silica solution does notpenetrate sufficiently deep into the exposed surface of the concreteslab then the aggregate may detach from the concrete slab as pedestrianswalk over the aggregate due to the detrimental chemical reaction ofreactive aggregate and the concrete. The solution must be applied at acertain temperature, specifically, between 50° F.-100° F. In coldenvironments, this means that the concrete slab with exposed surfaceseeded aggregate can only be formed during certain times of the year.Also, with the application of the hydrolyzed alkali silica solution,additional steps and care must be taken in curing the uncured concrete.The application of the hydrolyzed alkali silica solution also adds timeand expense to the construction project since it is an extra step overand above forming the concrete and distributing the aggregate onto theconcrete.

Concrete slabs are also formed in various environments. One environmentin which concrete slabs do not particularly do well in is environments,which reach freezing temperatures on a cyclical basis. The reason isthat concrete slabs are porous which absorb water. When the waterabsorbed in the concrete slab freezes, the frozen water expands andapplies pressure in the pores of the concrete. If the pressure exceedsthe strength of the concrete, then the cavity will deteriorate. Thecumulative effects of successive freeze-thaw cycles eventually createcracking, scaling, crumbling and eventual failure of the concrete slab.To address the detrimental effects of freeze-thaw damage, the concreteslab is entrained with a large number of closely spaced small airbubbles. The air bubbles relieve the pressure caused by ice formation byacting as expansion chambers. Unfortunately, this is an imperfectsolution.

Accordingly, there is a need in the art for an improved method foraddressing the issue of alkali silica reaction when embedding certainaggregate at the exposed surface of a concrete slab. There is also aneed in the art for an improved method for resolving the detrimentaleffects of freeze-thaw and addressing both the issue of alkali silicareaction when embedding aggregate and freeze thaw.

BRIEF SUMMARY

The various aspects disclosed herein address the needs discussed above,discussed below and those that are known in the art.

In the method disclosed herein, the method addresses the issue of alkalisilica reaction when embedding reactive aggregate into a concrete slab.Instead of applying a hydrolyzed alkali silica solution to the exposedsurface of the concrete slab, a waterproofing admixture is added to theconcrete mix. This allows the construction of the concrete slab withexposed embedded concrete at temperatures below 50 degrees F. and above100 degrees F. Moreover, after uniformly mixing the waterproofingadmixture to the concrete mix, the concrete mix is handled and cured asnormal.

The mixture of waterproofing admixture and concrete mix may also be usedto mitigate the detrimental effects of freeze-thaw. The concrete slabneed not be entrained with air to relieve pressure caused by frozen ice.

The method disclosed herein includes the step of mixing a waterproofingadmixture with the concrete mix to produce a waterproof concrete mix.The waterproof concrete mix may be utilized to address one or both of(1) alkali silica reaction when embedding reactive aggregate in concreteand/or (2) the freeze thaw issue. By way of example and not limitation,the waterproof concrete mix (i.e., mixture of waterproofing admixtureand concrete mix) may be used to form the concrete slab at a locationsubject to freezing temperatures and to address the detrimental effectsof the freeze-thaw without, embedding aggregate at the exposed surfacethereof. Additionally, the waterproof concrete mix may be utilized toform a concrete slab at a location subject to freezing temperatures withaggregate embedded at that exposed surface of the concrete slab allwithout entraining the concrete slab with air or utilizing a surfaceretarder as discussed in the prior art references. The waterproofconcrete mix may also be utilized in locations not subject to freezingtemperatures embed aggregate at the exposed surface of the concreteslab. The waterproof concrete mix is versatile in that it can beutilized to address one or both of the freeze-thaw issue or facilitateembedment of aggregate at the exposed surface of the resulting concreteslab.

More particularly, a method of producing a concrete slab having anexposed surface seeded aggregate is disclosed. The method may comprisethe steps of providing a concrete mixture having a waterproof admixtureto produce a waterproof concrete mix; after the providing step, pouringthe waterproof concrete mix over the subgrade, the waterproof concretemix defining an exposed surface when poured; bringing up a quantity ofcement/fines paste to the exposed surface of the waterproof concretemix; broadcasting a quantity of aggregate upon the exposed surface ofthe waterproof concrete mix; mixing the quantity of aggregate into thequantity of cement/fines paste; and curing the waterproof concrete mix.The aggregate used in the method may be selected from the groupconsisting of glass, silica glass, organic materials, sea shells, coursesand, Monterey Aquarium course sand and mollusk. The aggregate used inthe method may be prone to alkali-silica reaction. The waterproofingadmixture mitigates the alkali-silica reaction between the alkali-silicaprone aggregate and the concrete mixture to facilitate secure embedmentof the alkali-silica prone aggregate in the concrete slab. The aggregateused in the method may be glass, silica glass, organic materials, seashells of marine animals and mollusk, metal, composite materials andcombinations thereof.

In the method, the bringing up step may be accomplished with a vibratingmetal bull float. In the method, the mixing step may be accomplishedwith a vibrating metal bull float.

The method may further comprise the step of finishing the exposedsurface of the concrete mixture with a power trowel to facilitate aneven distribution of the quantity of aggregate, within the quantity ofcement/fines paste.

In the method, the pouring step may include the step of pouring thewaterproof concrete mix over the subgrade at a location subject tofreezing temperature, wherein the waterproofing admixture mitigatesdetrimental effects of freeze thaw on the concrete slab.

In another aspect, a method of forming a concrete slab which mitigatesdetrimental effects of freeze-thaw is disclosed. The method may comprisethe steps of forming a subgrade at a location subject to freezingtemperatures; providing a concrete mixture having a waterproof admixtureto produce a waterproof concrete mix; after the providing step, pouringthe waterproof concrete mix over the subgrade at a location subject tofreezing temperatures, wherein the waterproofing admixture mitigatesdetrimental effects of freeze thaw to the concrete slab.

In the method, the waterproofing admixture may transform into a polymerto mitigate absorption of water into the concrete slab. Alternatively,the waterproofing admixture may generate a crystalline formation tomitigate absorption of water into the concrete slab.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features and advantages of the various embodimentsdisclosed herein will be better understood with respect to the followingdescription and drawings, in which like numbers refer to like partsthroughout, and in which:

FIG. 1 is flow chart for mixing a water proof admixture and concretemixed to produce a waterproof concrete mix which is subsequently used toform a concrete slab;

FIG. 2 illustrates a flow chart for forming a concrete slab at alocation subject to freezing temperatures and mitigating the detrimentaleffects of freeze-thaw;

FIG. 3 is a cross-sectional view of a concrete slab formed at a locationsubject to freezing temperatures to address the detrimental effects offreeze-thaw;

FIG. 4 illustrates a flow chart of a method tor embedding aggregate uponan exposed surface of a concrete slab; and

FIG. 5 is a cross sectional view of the concrete slab with embeddedexposed surface seeded aggregate using the method shown in FIG. 4.

DETAILED DESCRIPTION

Referring now to the drawings, the method disclosed herein utilizes awater proofing admixture 10 which is mixed in with a concrete mix 22 forthe purposes of facilitating embedment of aggregate 16 into an exposedsurface 18 of the concrete slab 14 a and/or preventing cracks in aconcrete slab 14, 14 a due to freeze-thaw. The resultant mixture of thewaterproofing admixture 10 and concrete mix 12 shall be referred to aswaterproof concrete mix 20. Once the water proofing admixture 10 and theconcrete mix 12 are homogenously mixed, the waterproof concrete mix 20is poured over a subgrade 22 to form 50 a concrete slab 24, 24 a. Theconcrete slab 24, 24 a to be formed with the waterproof concrete mix 20may be formed at a location subject to freezing temperatures. Thewaterproofing admixture 10 prevents absorption of water or liquid intothe concrete slab 24, 24 a. As such, when the environmental temperaturereaches freezing temperatures, no liquid is disposed within the concreteslab 24, 24 a and the concrete slab 24, 24 a does not experience thedetrimental effects of repeated freeze-thaw cycles. If aggregate 16 issurface seeded into the concrete slab 24 a, then a vibrating metal bullfloat is worked on the exposed surface 18 after pouring the waterproofconcrete mix 20 over the subgrade 22 to dispose a quantity ofcement/fine paste 26 of the waterproof concrete mix 20 at the exposedsurface 18. A quantity of aggregate 16 is then disposed over the exposedsurface 18 and evenly distributed thereon. The aggregate 16 is mixedinto the cement/fines paste 26. The waterproof concrete mix 20 is thenallowed to cure to form the concrete slab 24 a. The aggregate is nowembedded at the top surface of the concrete slab. No special care needbe taken other than to embed the concrete and cure the concrete. Themethod of forming the concrete slab 24, 24 a may be utilized in alllocation including locations that reach freezing temperatures as well asthose that do not. Moreover, the method disclosed herein permitsformation of a concrete slab 24 a with surface seeded aggregate 16 notonly in moderate temperature locations but also in locations which reachfreezing temperatures. Moreover, the method disclosed herein forembedding surface seeded aggregate 16 into the concrete slab 24 a doesnot require application of a hydrolyzed alkali silication solution andthe special care of applying such solution.

More particularly, referring now to FIGS. 1-3. in preparing 100 asubgrade 22, the ground may be excavated to a desired elevation andgrade. The subgrade 22 is preferably compacted to 90% compaction. Alayer of clean, moist coarse sand 28 is preferably poured over thesubgrade 22 and maintained at a minimum four (4) inch thickness. Thesand 28 is not necessary for addressing freeze-thaw or producing thesurface seeded aggregate concrete slab 24 a but is preferable to controlthe hydration process of the concrete slab 24, 24 a. If it is desired toincrease the resultant strength of the concrete slab 24, 24 a and reducesubsequent cracking of the same, reinforcement members 30 such as a wiremesh or rebar is/are positioned upon the layer of sand 28.

A water proofing admixture 10 is mixed 102 in with a concrete mix 12 toproduce a waterproof concrete mix 20, as shown in FIG. 1. The admixture10 may be provided in powder form and added to the drum of a ready-mixtruck. The ready mix truck may be driven under a batch plant and thebalance of tire materials may be added to the ready mix truck inaccordance with standard concrete practices. The admixture 10 and theconcrete mix 12 may be mixed to ensure a homogenous mixture of theadmixture 10 and the concrete mix 12. Alternatively, water may be addedto the dry water proofing admixture 10 to form a slurry. The slurry ispoured into the ready mix truck. The aggregate, cement and water arebatched and mixed in accordance with cement practices taking intoaccount the water that has already been placed in the ready mix truck.In a further alternative, the admixture 10 may be added to rock and sandand then mixed thoroughly to provide for a homogenous mixture. Cementand water are then added and blended using standard practices. Althoughthe waterproofing admixture 10 may be mixed in with the concrete mix 12at a batch plant, it is also contemplated that the waterproofingadmixture 10 maybe mixed in with the concrete mix 12 at the job site.

The water proofing admixture 10 may be an admixture sold under the tradename XYPEX admix or HYCRETE. By way of example and not limitation, thewaterproofing admixture 10 may transform into a polymer to mitigateabsorption of water into the concrete slab 24, 24 a. Alternatively, thewaterproofing admixture 10 may generate a crystalline formation tomitigate absorption of water into the concrete slab 24, 24 a.

The waterproof concrete mix 20 is poured 104 over the subgrade 22 toapproximately 3½ to 4 inch thickness. If fill sand 28 and reinforcementmembers 30 are used, then the waterproof concrete mix 20 is poured 104over the layer of fill sand 28 and the reinforcement members 30 suchthat the reinforcement members 30 are encapsulated within the waterproofconcrete mix 20. After the waterproof concrete mix 20 has been poured104 on the subgrade 22, the uncured concrete is preferably screeded to adesired level plane or grade. The screeding of the concrete mixtureresults in defining a generally level of planar upper exposed surface18. The concrete mixture may be cured 106 according to standardpractices. When the above concrete slab 24 is formed at a locationsubjected to the detrimental effects of freeze-thaw, the concrete slab24 which is now waterproof prevents entrapment of water in the pores ofthe concrete slab 24 to mitigate the detrimental effects of freeze-thaw.

The above concrete slab 24 mitigates the detrimental effects offreeze-thaw. Moreover, referring now to FIGS. 4 and 5, a concrete slab24 a with embedded aggregate may be formed utilizing the waterproofingadmixture 10 wherein the surface seeded concrete slab 24 a may be formedin locations subject to freezing temperatures as well as non freezingtemperatures. To this end, the subgrade 22 is prepared 100 in much thesame way as discussed above. Additionally, the waterproof concrete mix20 is prepared 102 in the same way as discussed above. Put simply, thewaterproofing admixture 10 is mixed 102 homogenously into the concretemix 12 prior to pouring the waterproof concrete mix 20 over the subgrade22. After adding the waterproofing admixture 10 with the concrete mix12, the waterproof concrete mix 20 is poured 104 over the subgrade 22and if used, the fill sand 28 and reinforcement members 30 so that, thewaterproof concrete mix 20 encapsulates the reinforcement members 30.

The uncured concrete is screeded to a desired level plane or grade so asto define the exposed surface 18. The uncured concrete is not tamped asis conventional in the art. Tamping should be avoided so as to not bringup too much cement/fines paste 26 in the waterproof concrete mix 20which would be prohibitive for the subsequent surface seeding of theexposed aggregate 16 thereupon. Rather, after screeding, the exposedsurface 18 of the uncured concrete is surfaced or finished with avibrating bull float to dispose a quantity of cement/fines paste 26derived from the waterproof concrete mix 20 at the exposed surface 18 asshown in FIG. 5. The vibrating metal bull float is characterized bypossessing an extremely smooth or polished surface which seals theexposed surface 18 and also brings up 108 the appropriate amount ofcement/fines paste 26. By way of example and not limitation, thevibrating metal bull float may be a vibrating magnesium or aluminum bullfloat. The vibrating metal bull float may be a float sold under thetrademark HAL 200 by the Lievers Holland company.

After bringing up 108 the cement/fines paste 26 as discussed above andwhile the uncured concrete 20 is still plastic, small sized aggregate 16is distributed 110 over the exposed surface 18 of the uncured concrete20. The aggregate 16 may have a mean diameter size of about ⅜ inch orsmaller. By way of example and not limitation, the mean diameter sizemay be about ⅜ inch, ¼ inch or ⅛ inch. The aggregate 16 may or may notbe susceptible to alkali silica reactivity. By way of example and notlimitation, the aggregate 16 may be silica sand, glass bead, coarse sandsuch as Monterey Aquarium coarse sand, organic materials such as seashells, metals, or composite materials. The aggregate 16 may also besusceptible to alkali-silica reactivity such as glass, silica glass,organic materials, sea shells of marine animals, mollusk, metals andcomposite materials. Although the aggregate 16 may be susceptible toalkali-silica reactivity, the method disclosed herein mitigatesalkali-silica reactivity due to the waterproofing admixture 10 in theconcrete mix 12. Alternatively, the aggregate may be an aggregate thatis not prone to alkali-silica reactivity such as coarse sand, MontereyAquarium (Grade) course sand. The aggregate 16 may have rough jagged,sharp or round smooth external surfaces.

The aggregate 16 is distributed 110 over the exposed surface 18 of theuncured concrete 20 at a preferred rate of about 1 pound per square footof the exposed surface 18 of the uncured concrete 20. During thisbroadcasting step 110, the aggregate 16 should preferably not initiallydepress below the exposed surface 18 of the uncured concrete 20 but bedistributed to solely cover the exposed surface 18. The distribution ofthe aggregate 16 is preferably done in an even manner. The aggregate 16may be distributed 110 with a square tip shovel when distributing 110aggregate 16 up to 10 feet away from the person operating the shovel.When the aggregate 16 needs to be distributed 110 over a large surfacearea or more than 10 feet and up to 24 feet away from the operator, theaggregate 16 may be distributed 110 utilizing a material spraying devicesuch as a Goldblat material sprayer or a sand blaster. Use of a materialspraying device allows for a uniform distribution of the aggregate 16equal to or better than the uniformity achievable through manualdistribution with a square point shovel.

Although an even distribution of aggregate 16 is contemplated, it isalso contemplated that a non even distribution of aggregate 16 may bedisposed over the uncured concrete 20. By way of example and notlimitation, the aggregate 16 may be formed over a small patch on theuncured concrete. Alternatively, the aggregate 16 may be disposed overthe uncured concrete 20 in the form of a letter or other pattern.

Subsequent to broadcasting 110 the aggregate 16, the aggregate 16 isthen worked into 112 the cement/fines paste 26 that was previouslybrought up 108 to the exposed surface 18 of the uncured concrete 20. Tothis end, the vibrating metal bull float (e.g., magnesium or aluminum)may be used to work 112 the aggregate 16 into the cement/fines paste 26to ensure that the aggregate 16 is fully embedded into the cement/finespaste 26, and thus, thoroughly adhered or bonded to the exposed surface18 of the cured concrete.

After working or embedding 112 the aggregate 16 into the cement/finespaste 16, the exposed surface 18 may be finished with a power trowel tofurther facilitate even distribution of the aggregate 16 within thecement/fines paste 26.

After finishing the exposed surface 18 with the power trowel, a vaporbarrier is preferably formed on the exposed surface 18 of the uncuredconcrete 20. By way of example and not limitation, the formation of thevapor barrier may be facilitated by the application of a liquid chemicalevaporation reducer to the exposed surface of the uncured concrete. Apreferred evaporation reducer is sold under the trademark CONFILM by theConcrete Tie company of Compton, Calif. Alternatively, a vapor barriermay be formed by covering the exposed surface with four or six millvisqueen. The vapor barrier may be maintained upon the exposed surfaceof the uncured concrete 20 for a prescribed period of time, which mayrange from approximately two to twenty-four hours.

After the vapor barrier has remained upon the exposed surface 18 for theprescribed period of time, the exposed surface 18 of the uncuredconcrete 20 is washed with water to remove any surface films. Thewashing procedure may also include the step of lightly brushing theexposed surface 18 with a bristle. The brushing is preferably performedso that no more than about 5% of the aggregate 16 is dislodged andremoved from the exposed surface 18. The extremely low percentage (i.e.,less than 5%) removal of the aggregate 16 from the exposed surface 18evidences the extremely strong adherence of the aggregate 16 to theexposed surface 18 of the concrete. The application of the liquidevaporation reducer to the exposed surface 18 which prevents hydrationof the uncured concrete and reduces the rate of evaporation of moisturefrom the uncured concrete 20 increases the ease at which excesscement/fines paste 26 are washed from the exposed surface 18 during thisinitial washing step.

After washing, the concrete mixture 16 may be cured 106 with water onlyas opposed to chemical curing agents to avoid any staining of the same.Water curing 106 may be facilitated through the use of a conventionalfogger or soaker hose. After a prescribed period of time (e.g., 30 daysafter initiating the curing process) any surface residue present on theexposed surface 18 may be removed by conventional power washing with a90% steam and 10% muriatic acid mixture which is applied by a powerwasher via a high pressure nozzle.

The resultant surface seeded exposed aggregate concrete exhibits anextremely flat exposed aggregate surface which is suitable for extremelyhigh pedestrian traffic flooring applications. Additionally, exposedsurface of the concrete slab may be modified so that the surface colorand texture approximates the surface color and texture of moreconventional flooring surfaces such as stone, granite and marble. Thisresemblance can further be accentuated by saw cutting the concretesurface into rectangular grids to give the appearance that theindividual rectangular squares of the grid were laid in a manneranalogous to stone, granite or marble flooring.

The addition of the waterproofing admixture 10 to the concrete mix 12mitigates the detrimental effects of freeze-thaw in concrete slabs forlocations that reach freezing temperatures. Moreover, the addition ofthe waterproofing admixture 10 to the concrete mix 12 also mitigatesalkali-silica reaction when alkali-silica reaction prone aggregate 16 issurface seeded into the concrete slab. The alkali-silica reaction isformed between the chemical reaction between the concrete mix 12 andaggregate 16 that is susceptible to alkali-silica reactivity. Thewaterproofing admixture 10 mitigates the alkali silica reaction whenalkali silica reaction prone aggregate 16 is used so that a surfaceretarder is not needed to ensure secure embedment of the aggregate 16into the concrete slab. The waterproofing admixture 10 helps to ensurethat the surface seeded aggregate remains embedded in the concrete evenwith high pedestrian traffic application. Also, waterproofing admixturealso mitigates the detrimental effects of freeze-thaw.

The method disclosed herein may be useful for forming a concrete slab24, 24 a with or without aggregate 16 embedded in the exposed surface 18regardless of whether the concrete slab 24, 24 a is formed at locationssubject to freezing temperatures. However, the method disclosed hereinallows a contractor to form a concrete slab 24 a with surface seededaggregate 16 at a location subject to freezing temperature by addressingboth 1) the embedment of the aggregate 16 in the concrete slab 24 a and2) mitigating the detrimental effects of freeze thaw simultaneouslyinstead of separately with two different processes.

In the method described herein, the vibrating metal bull float may bereplaced with any type of float such as a bull float, metal bull floatand a wooden float. By use of the term vibrating metal bull float or anyspecific type of float herein, the various aspects disclosed hereinshould not be limited to the same but the method may incorporate the useof other types of floats known in the art or developed in the future.

The above description is given by way of example, and not limitation.Given the above disclosure, one skilled in the art could devisevariations that are within the scope and spirit of the inventiondisclosed herein, including various ways of mixing the waterproofingadmixture and concrete mix together. Further, the various features ofthe embodiments disclosed herein can be used alone, or in varyingcombinations with each other and are not intended to be limited to thespecific combination described herein. Thus, the scope of the claims isnot to be limited by the illustrated embodiments.

What is claimed is:
 1. A method of producing a concrete slab having anexposed surface seeded aggregate, the method comprising the steps of:providing a concrete mixture having a waterproof admixture to produce awaterproof concrete mix; after the providing step, pouring thewaterproof concrete mix over the subgrade, the waterproof concrete mixdefining an exposed surface when poured; bringing up a quantity ofcement/fines paste to the exposed surface of the waterproof concretemix; broadcasting a quantity of aggregate upon the exposed surface ofthe waterproof concrete mix; mixing the quantity of aggregate into thequantity of cement/fines paste; and curing the waterproof concrete mix.2. The method of claim 1 wherein the aggregate is selected from thegroup consisting of glass, silica glass, organic materials, sea shells,course sand, Monterey Aquarium course sand and mollusk.
 3. The method ofclaim 1 wherein the aggregate is prone to alkali-silica reaction and thewaterproofing admixture mitigates the alkali-silica reaction between thealkali-silica prone aggregate and the concrete mixture to facilitatesecure embedment of the alkali-silica prone aggregate in the concreteslab.
 4. The method of claim 3 wherein the aggregate is glass, silicaglass, organic materials, sea shells of marine animals and mollusk,metal, composite materials and combinations thereof.
 5. The method ofclaim 1 wherein the bringing up step is accomplished with a vibratingmetal bull float.
 6. The method of claim 1 wherein the mixing step isaccomplished with a vibrating metal bull float.
 7. The method of claim 1further comprising the step of finishing the exposed surface of theconcrete mixture with a power trowel to facilitate an even distributionof the quantity of aggregate within the quantity of cement/fines paste.8. The method of claim 1 wherein the pouring step includes the step ofpouring the waterproof concrete mix over the subgrade at a locationsubject to freezing temperature, wherein the waterproofing admixturemitigates detrimental effects of freeze thaw on the concrete slab.
 9. Amethod of forming a concrete slab which mitigates detrimental effects offreeze-thaw, the method comprising the steps of: forming a subgrade at alocation subject to freezing temperatures; providing a concrete mixturehaving a waterproof admixture to produce a waterproof concrete mix;after the providing step, pouring the waterproof concrete mix over thesubgrade, wherein the waterproofing admixture mitigates detrimentaleffects of freeze thaw on the concrete slab.
 10. The method of claim 9wherein the waterproofing admixture transforms into a polymer tomitigate absorption of water into the concrete slab.
 11. The method ofclaim 9 wherein the waterproofing admixture generates a crystallineformation to mitigate absorption of water into the concrete slab.